abs function equivalent in c++

Hi everyone, I am presently struggling with converting a matlab prototype code into a c++ equivalent. I am struggling with the abs function.

What should I do in C++/C to get the similar output?

Answer 1

[Walter Roberson]

https://cplusplus.com/reference/cstdlib/abs/

In C++ abs() is overloaded and for double precision will call fabs()

fabs() was not a formal part of C, but it was common for C vendors to provide fabs(). It was common for fabs to be implemented as a macro, but that led to arguments, especially as ieee 754 double precision defines an fabs hardware operation that does not require any branching.

[Manu Chaudhary]

Thank for the response.

Your link provide a abs method for c++.

But if suppose, the problem is

abs(0.234 +j0.43)^2 + abs(0.24 +j0.643)^2

Then what should I do in C++?

Do the term like below make sense or do it require some change.

n=pow(abs(0.234),2) + pow(abs(0.43),2) + pow(abs(0.24),2) + pow(abs(0.643),2);

Thank you in advance.

[Manu Chaudhary]

Thank you for great help. Your solution worked.

[Walter Roberson]

https://en.cppreference.com/w/cpp/numeric/complex shows the complex class for C++ and shows using a suffix of i for imaginary part, and shows abs() as the function name